System of control



R. E. HELLMUND. SYSTEM OF CONTROL.

APPLICATION FILED MAR. 13, 1920.

1 60,746 Patented Nov. 30, 1920.,

NVENTOR :i'TtED STATES PATENT OFFICE.

RUDOLF E. HELLMUND, 0F SWISSVALE, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC AND IMANUFACTURING CC'MPANY, A CORPORATION OF PENN- SYLVANIA.

SYSTEM OF CONTROL.

Specification of Letters Patent.

Patented Nov. 30, 1920.

Originalapplication filed January 5, 1916, Serial No. 70,437. Divided and this application filed March 13, 1920. Serial No. 365,397.

vlo all whom it may concern:

Be it known that I, RUooLr E. HELL- MUND, a citizen of the German Empire, and a resident of Swissvale, in the county of Allegheny and State of Pennsylvania, have invented a newand useful Improvement in Systems of Control, of which the following is a specification, this application being a division of my co ending application, Serial No. 70,437, filed anuary 5, 1916.

My invention relates to electrically-propelled vehicles and: to systems of control therefor and especially to vehicles that are driven by a plurality of induction motors.

Gne object of my invention is to provide, in connection with a system of the above indicated character, means which shall be relatively simple and inexpensive in construction and effective and reliable in operation for automatically .sanding the rails when any set of driving 'wheels.slip's, that is, rapidly rotates without'gripping the rails.

According to my present invention, I provide electrical relay means that are electrically connected with the rotors of the several driving induction motors and are adapted to counter-balance each other under normal and substantially equal-speed conditions of the motors but which are adapted to produce an unbalanced effect under predetermined unequal rotor-speed conditions, such as occur upon the slippage of one motor and the corresponding wheels, and I associate with the relay means certain switching means for automatically effecting adequate sanding of the rails to assist in restoring normal conditions.

In the accompanying drawings, Figure 1 is a diagrammatic view of an electric locomotive unit embodying a plurality of driving motors to which my invention may be applied; Fig. 2 is a diagrammatic view of the essential circuits of a system of control embodying my invention; and Fig. 3 is a diagrammatic view, showing the details of construction of a portion of the apparatus that is shown in Fig. 2.

Referring to Fig. 1, the structure shown comprises a. locomotive cab 1 which is suitably supported upon a plurality of articulated trucks 2 and 3 of suitable design and which respectively embody a plurality of driving wheels a and 5, that are adapted to run upon rails 6, in accordance with usual practice. A plurality of driving induction motors M1 and M2 are provided and may be associated with the wheels of the various trucks in any suitable manner, as by driving mechanisms 7 and 8 of a familiar type.

Referring now to Fig. 2, the system shown comprises a plurality of suitable three-phase supply-circuit conductors A, B and C; the driving induction motors M1 and M2 that may respectively comprise delta-connected primary windings P1 and P2 and cooperating delta-connected secondary or rotor windings S1 and S2; a plurality of suitable variable accelerating resistors LRl and LE2 for the rotor windings S1 and S2 respectively; a plurality of main-circuit switches LS1, LS2 and LS3 for connecting the primary winding P1 to the supply-circuit conductors; a plurality of similar switches LS4, LS5 and LS6 for performing a similar function with respect to the primary winding P2; a plurality of auxiliary induction motors AMl and AM2 that are associated with the main rotor windings S1 and S2 in a manner and for a purpose to be described; an auxiliary source of ener y, such as a battery B; a

' sanding device D and a starting switch SW'.

The variable resistors LRl and LE2 are here shown as comprising resistors of the familiar liquid-rheostat type and severally embodying suitable electrolyte-containing tanks or chambers 11, within which are disposed a plurality of suitable immersible plates or electrodes 12, as is customary; and lower compartments 13 from which the electrolyte may be pumped into the tanks 11 and to which the electrolyte may be returned in accordance with the actionof suitable regulating and discharge valves 14; that are more fully described in a Patent, No. 1,300,383, granted to Arthur J. Hall on April 15, 1919, and assigned to the lVestinghouse Electric & Manufacturing Company. Inasmuch as the particular type of rheostat and the structural details thereof are immaterial to my present invention, I do not deem it necessary to describe the same any further.

' The electrodes or plates 12 of the rheostat LE1 are respectively connected to the terminals of the secondary winding S1 by conductors 15, 16 and 17, and the electrodes of the other rheostat LE2 are similarly connected to the secondary winding S2.

The operating mechanism for each of the valves 14, whereby electrolyte is admitted to when the piston 102 is located at the other end thereof. The rod 103 is connected to a cord or cable 104 that passes over a pulley 105 and. has. a suitable counterbalancing weight 106attached to its outer end. A pair of standard magnet valves 107 and 108 are associated with the respective ends of the cylin'der101 for a'dmittingfluid pressure to theone or the other side of the piston 102 in accordance with the energization of the respective valve magnets. The other liquid rheostat L112 is provided with a similar pair of operating valve magnets 109 and 11.0. 7

The electrical relaymeans that here coni- '=prise the auxiliary induction motors A1111 and'AM2 are more clearly structurally illustratedin Fig. 3. The auxiliary induction motorsrespectivelycomprise stators 30 and .31, and squirrel-cage rotors 32 and 33 that are rigidly mounted upon a suitable shaft 34 the ends of which are carried in suitable bearings '35 and 36 that are respectively supported by pedestals or brackets 37 and 38.

Thestators 30 and 31 are severally pro- "vided with suitable phase windings 39 and with bearings 40 on the shaft 34, whereby the-stators may rotatively move within predetermined limits, as about to be described,

under certain torque conditions.

The 'illlXlllaly"111(lL1Ct1OIl motors AMI and AM2 are respectively provided with switches 95 and; 96 that are movable with the re spective stators 30 and 31, within predetermined limits, and are provided with pairs of contactmembers 97 and 98 and 99 and 100, respectively, for purposes to be described. The'switches 95 and 96 are respectivelybiased to positions marked Dej crease by means of suitable springs 43, and

ing brackets 37 and 38, if desired.

in these positions the switches respectively rest against stops or pins 44 and 46 that are suitably associated with any stationary member, such as projections from the bear- 7 The switching devices 95 and 96 are also severally adapted to occupy second positions marked Increase when the stators 30 and 31- are actuated as far as second stops or pins 45 and 47, respectively, under predeterminedconditions to be 7 described later The terminals of the stator winding of the V auxiliary induction motor AMlare coning the sand to the rails nected to the respectiveterminals of the secondary winding S1 by conductors 48, 49 and 50, and the stator winding of the other auxiliary induction motor AM2 is similarly associated with the other main secondary winding S2. i V

The sanding device SD may comprise a suitable hopper 111,-an appropriate-valve member 112 that is associated with the core member 113 of the actuating coil Sand-1, and a suitable pipe or tube 114 for convey- 6 in front of the wheels 4. 3

Assuming that it'is desired toeffect acceleration of the driving motors, the switches LS1 to LS6, inclusive, may be closed inany suitable manner and the switch SW maybe actuated to its upper position marked Dec, crease, whereby a circuit is established from one terminal of the battery 13 through conductors 120 and 121,.the blade 122 of the switch SW stationarycontact member 123, conductors 124 andwl25, actuating coil 107 :of the operating mechanism of the liquid;

rheostat LE1, conductor 126,.controlfingers 127 and 128, which are bridged by contact member 97 of the switching device 95 inits normal position Decrease, and conductors 129, 130 and 131'to the-negativebattery terminal. A parallel circuit is completed from conductor 125 throughconductor 132, the actuating coil 109 of the operating mechanism of the rheostat LE2, conductor 133, control fingers 134 and 135, which are bridged by contact member 99 of the auxiliary switchingdevice 96, and conductors 136 and 138.130 the negative conductor 131. In this way, the operating mechanisms of the liquid'rheostats are actuated to admit electrolyte to the tanks 11 and gradually decrease the rotor-circuit resistances of the driving induction motors.

P To effect the discharge of the electrolyte from the tanks 11, the switch SWV may be actuated to its other position marked Inc. standing for increase,-whereupon one circuit is established from the blade 1220f the switch SW, through stationary contact member 1'39, conductor 140, actuating coil 108 of the liquid rheostat LE1, and conductor 141 to the negative conductor 130. A simultaneous circuit is completed from the switch blade 122 through stationarycontact member 142, conductors 143 and 144, actuating coil 110 of the liquid rheostat LR2 and conductor 145 to the negative conductor 131. Thus, fluid pressure is admitted above the pistons 102, the valves 14 areopened and the electrolyte is discharged from the tanks 11. Assuming that the wheels 4 that are associated with the driving motor M1 slip I while the switch SW occupies its position Dec, so that the primary current in the winding P1 is relatively low, while the speed 1 standing for de- 7 oi? the rotorwinding S1 is relatively high and its frequency low, the rotor 32 of the auxiliary induction motor AMl will tend to rotate at a lower speed that corresponds to the decreased speed of therotating field in the stator 30. However, such decreased speed will be prevented, at least partially, by the normal action of the mechanically associated rotor 33 of the other auxiliary induction motor tending to drive the rotor 32oversynchronously, so that a reactive or generator torque is exerted upon the stator 30, whereby the stator rotatively moves in a clockwise direction until the switching device 95 strikes the stop 4a and the switching device occupies its position Increase.

Consequently, a circuit is completedifrom one terminal of the battery B through conductor 146, control fingers 147 and 148, which are bridged by the contact member 97 of the switching device 95, conductors 1 19 and 14:0 and thence through the actuating coil 108 or" the liquid rheostat LE1. The other actuating coil 107 is simultaneously deenergized by reason of the disengagement of the contact member 97 from the control fingers 127 and 128. Thus, fluid pressure 'is admitted to thecylinder 101 above the piston 102 and is exhausted from below the piston through the valve that is associated with the magnet 107, and the resistance of the circuit of the rotor winding S1 is gradually increased until the speed of the slipping motor is reducedto normal when the normal motor torque, or such torque, assisted by the spring 43, if employed, will return the switching device 95 to the normal solid-line position.

The movement of the switching device 95 to its position Increase establishes anothercircuit at this time from the control finger 151 of the switching device 95, through conductors 154i and 155, the actuating coil Sand-1 of thesanding device SD and conductor 156 to the negative conductor 138.

It will be understood that, under slippage conditions of the other main motor M2, the switching device 96 is automatically actuated to its dotted-line position Inc., whereupon the slippage conditions are automatically eliminated and the actuating coil words, the resistance in the circuit of the rotor winding SR1 is increased until the speed of the rotor S1 has decreased to normal value, when the generator torque of the auxiliary induction motor AMl disappears and the normal motor torque, assisted by the spring 13, returns the switching device 95 to the position shown in the drawing.

It will thus be seen that I have provided simple and reliable means for automatically sanding the rails whenever a certain motor is slipping, thus tending to rapidly restore normal conditions.

I do not wish to be restricted to the specific circuit connections or arrangement and locacombination with a plurality of parallel con nected driving motors, of a rail-sanding apparatus, and electrical relay means associated with the several motors and dependent upon slippage conditions in any motor for automatically actuating said apparatus to sand the rails.

3. In an electrically-propelled vehicle, the combination with a plurality of driving induction motors suitably associated with the vehicle wheels, of an electrically-controlled rail-sanding apparatus, and electrical relay means associated with the respective main rotors and dependent upon frequency conditions in any motor for energizing said apparatus to sand the rails.

4c. In an electrically-propelled vehicle, the combination with a pluralityof driving induction motors suitably associated with the vehicle wheels, of an electrically-controlled rail-sanding apparatus, and means dependent upon relative variations in the rotor frequencies of said motors under slippage conditions of any wheels for automatically energizing said apparatus to sand the rails.

5. In an electrically-propelled vehicle, the combination with a plurality of driving induction motors suitably associated with the vehicle wheels, of an electrically-controlled rail-sanding apparatus, relay means having operating windings actuated in accordance with the frequencies of the respective rotors of said induction motors, said operating windings counterbalancing each other under substantially equal-speed conditions of said rotors and being adapted under predetermined unequal rotor-speed conditions to pro duce an unbalanced effect, and means dependent upon said unbalancing for automatic'ally energizing said apparatus to sand the rails.

6; In an electrically-propelled vehicle,'the combination with a plurality'of drivingin- V ductionmotors suitably associated with the vehicle Wheels, of an electrically-controlled rail-sandingapparatus, a plurality of auxiliary induction motors having mechanically associated rotors and'having their stators electrically connected with the respective main rotors and rotatively movable within 7 predetermined limits, whereby movement of the one or the other auxiliary stator from a normal position occurs only underv slippage subscribed my name induction motor, of means responsive to predetermined; variation from normal rotor frequency thereof for sanding the rails.

8.--The combination with a vehicle-driving induction motor, of a rail-sanding apparatus,

and means electrically responsive tothe r0- tor frequencyconditioiis of said motor for effecting actuation-of said apparatus I 9. The combination with a vehicle-driving induction motor, of airail-sanding apparatus,

and 7 electrical frequency controlled relay means connected with the rotor of said inotor-for effecting actuation of said apparatus under conditions ofrelatively rapid rotation 1 of said rotor.

Intestimony whereof, Iv have hereunto ary,--=l920. I

:IRUDoLF E. HELLMUND.

this 20th day of Febru- 

